Incinerator and ignition system combination

ABSTRACT

An incinerating waste disposal plant, such as a dry sanitary toilet, including a fuel burner and an oscillator ignitition system for igniting the fuel. In the system disclosed, the oscillator is one in which the core of the inductive component is driven to saturation and provides intermittent high voltage across an igniter spark gap.

United States Patent Frankel 1 Dec. 25, 1973 [54] INCINERATOR ANDIGNITION SYSTEM 2,600,928 6/1952 Semm .1 431/78 X COMBINATION 3,269,4478/1966 McCarty et a1... 431/78 X 3,291,183 12/1966 Fairley 431/78 X [75]Inventor: Donald P. Frankel, Lake Geneva,

Wis. Prima Examiner-Kenneth W. S ra ue [73] Assignee: lvuvaisMereIndustries, Inc., Walworth, Attomg; james F Coffee et a]. p g

[22] Filed: June 28, 1972 Appl. No.: 267,043

References Cited UNITED STATES PATENTS Kufrin et al 1 10/9 X [57]ABSTRACT An incinerating waste disposal plant, such as a dry sanitarytoilet, including a fuel burner and an oscillator ignitition system forigniting the fuel. In the system disclosed, the oscillator is one inwhich the core of the inductive component is driven to saturation andprovides intermittent high voltage across an igniter spark gap.

11 Claims, 3 Drawing Figures PATENT uIImsIsIs 3,780,677 sum 20$ 2IIIIIIIIIIIIIIIIIIIIIIHIIIIIIIIIIII FIG. 2

FIG. 3

/74 /a/ /84 FUEL FUEL RESERVOIR SUPPLY AIR [80 L TRACTION I76 I d MOTOR78 AIR INCllNElRATOR AND IGNITION SYSTEM COMBINATION BACKGROUND OF THEINVENTION 1. Field of the Invention This invention relates toimprovements in incinerating waste disposal plants and especiallyimprovements in dry sanitary incinerating toilets. The invention alsorelates to incinerating toilets especially adapted for installation inthe field or in moving vehicles, relying on a DC. source of electricity.

2. Brief Description of the Prior Art Incinerating toilets are becomingmore and more important as pollution problems grow. For example, suchtoilets have found use in residences where suitable waste disposal isnot available, camping areas, military camps, in installations onvehicles such as house trailers and diesel trains, cottages, boat housesand many other areas. Usually such toilets operate utilizing a burningcycle followed by a cooling cycle for cooling the combustion chamberafter the waste is destroyed. It is important to have positive and sureignition of the burner in order to prevent fire hazards or evenexplosions.

Previous incinerating toilets designed for use in conjunction with a DC.source of electricity, e. g., in railroad locomotives, have employedexpensive inverters to change the D. C. current to 60 cycle A.C. so thatthe current can be used by standard A.C. components in the incineratingtoilet. One of the important roadblocks against using D.C. directly hasbeen the lack of a dependable ignition system which can use the 74 voltD.C. standard power on a locomotive.

SUMMARY OF THE INVENTION The present invention provides a new and usefulincinerating waste disposal plant in the form of a dry sanitary toilethaving a new and improved D.C. ignition system. The ignition system usesan oscillator to apply a high voltage across a spark gap. The highvoltage is produced as a rapid plurality of intermittent dischargesacross the spark gap such as to have the appearance of a continuousspark. The oscillator in the preferred form is one in which the core ofthe inductive component is driven to saturation.

While an illustrative embodiment of the invention is shown in thedrawings and will be described in detail herein, the invention issusceptible of embodiment in many different forms and it should beunderstood that the present disclosure is to be considered as anexemplification of the principles of the invention and is not intendedto limit the invention to the embodiment illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS cle, usually a diesel locomotive, withthe toilet of FIG.

1 installed thereon.

DESCRIPTION OF THE PREFERRED EMBODIMENTS To a large extent the presentinvention provides improvements and modifications in an incineratingtoilet such as that shown in Frankel et al U. S. application Ser. No.108,050 and, as background material and so far as description of thestructure and operation of an incinerating toilet is concerned, U. S.application Ser. No. 108,050 is hereby incorporated herein by reference.

Referring to FIGS. 1 and 3, the incinerating toilet includes a tear dropshaped cabinet 20 with a housing 22 and an outer side wall skirt 24secured by suitable spacer members to the housing 22 to define an airspace 26 between housing 22 and skirt 24. Air can enter air space 26 atthe bottom of skirt 24. Also, ports 28 are provided around the upperportion of housing 22 for entry of air into air space 29 within housing22 from space 26. Ports 28a (FIGS. 1 and 3) are also provided for moredirect entry of air into the lower portion of space 29.

Housing 22 also has a central waste receiving top opening 30 with a seat32, with seat opening 32a generally registering with the opening 30. Acover 34 is secured to a hinge rod 36 for pivotal movement with rod 36between a down or closed position and an up or open position. Spacers34a are provided on the bottom surface of cover 34 for spacing cover 34from seat 32 when cover 34 is in its closed position. Seat 32 is securedto brackets 37 which pivot on hinge rod 36 for raising and lowering seat32. Seat 32 also has spacers 32b for spacing it from the top wall of thehousing 22 when in down position.

Mounted in the bottom of cabinet 20 is a large and deep combustion potdefining the receiving and combustion chamber 38. The receiving andcombustion chamber 38 is insulated on its outer surface by layers ofhigh temperature (up to 2,000F. or higher) insulation indicatedcollectively at 40. An oil burner 42 is mounted at an elevated positionat about the lip of the receiving and combustion chamber 38 and traineddownward at an angle to the side wall of the receiving and combustionchamber, generally toward the center of the combustion chamber fordirecting a flame into the combustion chamber. The oil burnerillustrated is a Gulf-type aspirator burner (See Biber et al. US. Pat.No. 3,119,604) having the normal float chamber 46 with about a threeinch negative pressure lift front float chamber 46 to the burner 42. Oilis supplied to burner 42 from float chamber 46 through an oil line 48which includes and is controlled by a fuel solenoid or oil-flow controlvalve 54. A motor driven compressor can be used to supply air to burner42 via air line 50 as de scribed in the above mentioned Frankel et alapplication Ser. No. 108,050. The oil is aspirated by the air in theburner and upon ignition the burner supports a flame at its lower end.Oil from a suitable source of supply is delivered to the float chamber46 via an oil inlet line 52.

Alternatively a gas burner can be used, supplied with propane or likefuel from a tank or cylinder, e. g., aboard a locomotive.

As seen in FIG. 1 the oil burner igniter 44 includes a pair of closelyspaced electrodes 56 and 58 supplied with a high voltage from anoscillator 60 so that a spark is created between the electrodes spacedlaterally from the outlet of burner 42. An orifice or port 62 ismachined or cast into the wall of the burner air chamber at a 45 angleto the axis of the burner to direct a stream of air from the burner airchamber through electrodes 56 and 58 and into the flame cone area at theburner flame holding port. As the air passes through the spark gap ofigniter 44 it is apparently ionized by the spark and the ionized aircarries or blows the ignition spark into the cone of combustible sprayensuing from the end of burner 42. The spark thereby ignites the burnerand after ignition the orifice 62 continues to supply a small amount ofcombustion air directly to the flame, in addition to the combustion airused to atomize the fuel within burner 42.

In FIG. 2, the oscillator 60 is illustrated in detail. Oscillator 60includes a first controllable conduction device 100, as an NPNtransistor, a second controllable conduction device 102, as a second NPNtransistor, and a core 106 of magnetizable material which determines thefrequency of oscillation of the circuit. Essentially, the oscillatorcircuit operates as a free-running magnetic multivibrator in which thefrequency of oscillation is determined by the speed of magnetization ofthe material in core 106 and the strength of the magnetizing forces onthe core.

Core 106 is formed of magnetizable material such as permalloy 80(DU-37-6D), having a square crosssection, as three-eights three-eightsinches (9/64 square inches). The core 106 forms a part of a step-uptransformer having three primary windings and one secondary winding. Oneprimary winding 110 consists of 25 turns of number 36 wire wrapped aboutcore 106. A pair of primary windings 112 and 114 each consist of 76turns of number 36 wire wound bifilor about the core. A single voltagestep-up secondary winding 116 consists of 5,000 turns of number 42 wirewound about the core 106. The opposite ends of secondary winding 116 aredirectly coupled to leads 55 and thence to the electrodes 56 and 58which form a spark gap, having a distance therebetween of three-sixteeninch.

The transistors 100 and 102 are oppositely driven by primary windings112 and 114, respectively. To power the oscillator 24, a source of DCpotential is connected between a positive source terminal 120 and anegative source terminal 122, such as 78 volts DC. A 10 microfaradcapacitor 124 shunts the terminals 120 and 122. Positive terminal 120 iscoupled to a junction 126 to which one side of each of the primarywindings 112 and 114 is connected. The opposite side of winding 112 iscoupled to the collector electrode of transistor 100, the emitterelectrode of which is directly connected to negative terminal 122.Similarly, the opposite side of winding 114 is coupled to the collectorelectrode of transistor 102, and the emitter electrode is coupled tonegative terminal 122.

Primary winding 110 has one side directly coupled to the control or baseelectrode of transistor 100, and the other side coupled through a 0.02microfarad capacitor 130 and a parallel connected 470 ohm resistor 132and a 0.01 microfarad capacitor 134 to the control or base electrode oftransistor 102. The base-emitter junctions of both transistors 100 and102 are shunted by a pair of diodes 140 and 142, respectively. The baseelectrode of transistor 100 is also coupled through a 100 kilohmresistor 144 to positive terminal 120.

In operation, when potential is first applied across terminals 120 and122, some current passes through resistor 144 to the base of transistor100, forward biasing the transistor into its conducting state. Thisallows a current flow from terminal 120, junction 126, and throughprimary winding 1 12 and the conducting transistor 100 to negativeterminal 122. The primary windings 110, 112 and 114 are mutually coupledas indicated by the dots in FIG. 2. The current through primary winding112 induces a current in winding 110 which drives transistor harder intoconduction, resulting in a stronger current in winding 112, which inturn forward biases or drives transistor 100 still harder. The resultingregenerative action quickly saturates transistor 100. Depending on thespeed of magnetization of the material in the core 106, the core laterbecomes saturated.

When the core 106 saturates, the drive from winding 1 10 begins todecay. During the time transistor 100 was forward biased, capacitor 130had been charging with a positive polarity at the junction betweencapacitor 130 and capacitor 134. When the output of winding 110 startsto decay, capacitor is effective to drive transistor 102 into itsforward biased state. The resulting current through winding 114 reversesthe drive from winding 110, causing transistor 102 to be driven harderinto conduction. The resulting regenerative action is similar to theaction previously described for transistor 100. Capacitor 130 nowrecharges in the opposite direction so as to start transistor 100conducting again when the core 106 again saturates. Resistor 132 is usedto limit current drive to transistor 102, and capacitor 134 causes anincrease in the switching speed.

Oscillator 60 thus drives the core of the transformer into saturation atshort time period after the pair of transistors 100 and 102 arealternately switched from saturation to cut-off. The frequency ofoscillation is thus determined by the material in the core, and for thegiven illustrative values of components, is approximately 11 kilohertz.Due to the step-up action of the transformer, the secondary winding 116produces across the gap formed by electrodes 56 and 58 a peak outputvoltage of approximately 5,000 volts. The rapidity of intermittent peakout-put voltages (11,000 per second in the system described) across thegap creates a seemingly continuous spark, assuring combustion of thefuel-air mixture at burner 42. The spark is capable of lighting evensolid fuels such as paper, wood and coal.

Although the device as illustrated in FIG. 1 includes motor drivenexhaust blower 64 for exhausting the combustion chamber through vent 66,one form of the device for railroad use omits the blower 64 and reliesentirely on a venturi system for venting the combustion chamber 38 asdescribed in Frankel et a] application Ser. No. 108,050. Such a venturisystem is shown in FIG. 3 in the form of an induction Tee which includesa connector duct 166 for connecting the device to the exhaust outlet 66and an induction flue duct 168 for connection to a suitable ventingstack or flue. The induction Tee is driven by a source of pressure airsupplied by an air supply tube 170 which extends approximately to thecenter of the juncture of connector duct 166 and induction flue duct168. A connector 172 is provided at the lower end of tube 170 forconnecting tube 170 to a suitable high volume source of air so that aircan be delivered upward through tube 170 to create a venturi effect fordrawing combustion gases from outlet 66 and through the connector duct166. The combustion gases are vented upward by the induction flue duct168 to the exterior. Downward or side venting can also be used. Theventuri venting effect can be used either in addition to or in theabsence of the blower fan 56.

FIG. 3 diagrammatically illustrates the incinerating toilet mounted on alocomotive, caboose or elsewhere on a railroad train. A wheeled carriagesuchas a diesel locomotive is represented generally by the referencenumeral 200. The locomotive 200 is equipped with a conventional dieselfuel tank 174, an air brake reservoir 1'76 and one or more tractionmotor blowers providing a source of air at low pressure and at highvolume as represented by traction motor air box 178. A fuel line 180extends from the fuel oil reservoir 174 to fuel oil line 52 and includesa DC. fuel oil cut-off solenoid valve 181 and a pressure reducing valve182 for reducing pressure of oil (or gas) supplied from tank 174, inthis case diesel fuel. The fuel in a diesel fuel tank is boosted to 30to 35 psig pressure before injection into the engine so a pressurereducing valve 182 is used to reduce the pressure to a much lower level,e.g., about 8 psig or less, for delivery to the float valve chamber 46and subsequent delivery to the burner 42. A filter 185 is also providedin the fuel line 180.

An air line 186 extends from the air brake reservoir 176 through apressure reducing valve 188 and a DC on-off control solenoid 190 andconnects to air line 50 to supply combustion air to burner 42. Thepressure reduction valve 188 reduces the pressure of air from the airbrake reservoir from its normal pressure of about 140 psig to a muchlower pressure, e.g., about 4 psig, for use by the burner 42.

Traction motor cooling blowers are used in a locomotive to blow air overand cool the traction motors. A small portion of this high volume lowpressure air represented at 178 is delivered through a duct as shown at192 which is connected at connector 172 for directing the air upwardlythrough tube 170 to drive the induction Tee or venturi system forexhausting the dry sanitary toilet. Where traction motor air is notavailable, a blower can be used. The outlet of flue duct 178 is ventedby suitable duct work 192 to the exterior through the roof (or floor,depending on venting arrangement) of the locomotive. Because the sourcesof fuel combustion air and venturi actuating or exhausting air arereadily available on the locomotive, the dry sanitary toilet unitprovides for very convenient installation in minimal overall space.Further, the device does not depend on actual motion of the locomotivefor operation.

At times and especially during the hot summer months when ambienttemperatures in the short hood section of a locomotive are often as highas 120F., it is desirable to cool the oscillator. For this purpose asmall air bleed line 196 is connected to line 50 and the outlet end ofbleed line 196 is positioned near oscillator 60 for the purpose ofblasting a small amount of air onto the oscillator box. As the airleaves the bleed line 196 there is also a small amount of expansion ofthe air which results in a small amount of actual refrigeration. Thisprovides for a cooler running oscillator without the expense of a largeheat sink.

The unit includes the rear top cabinet 202 which contains all of theelectrical components needed for the operation of the device, e. g., theoscillator circuit, fuel and air control solenoids 181 and 190 and/or54, pressure reducing valves 182 and 188, and flame sensor system. Otherelectrical components, when used, can also be mounted in cabinet 202 forquick and convenient access as described in Frankel et al applicationSer. No. 108,050. The device can also employ the variable vent 204, theheat sensitive cooling switch, the sail switch 206, the timer system,and the trap door 208 and linkages and other features described byFrankel et al. In using the incinerating toilets of the presentinvention, it has been found that a single device can readilyaccommodate the requirements of a crew of 12 men each working day withan average of five uses per man per day. The sterilizing flame destroysall bacteria and virtually eliminates any pollution problems. The devicedoes not involve any water consumption or use of chemicals and does notproduce raw sewage or cause any problems with regard to flushing andemptying, handling or pumping or the pollution dangers of operating awater toilet for as many as 60 times a day. The device is easilyserviceable and inexpensive to operate, costing only pennies a day forfuel. it can be installed in towers, shops, work-sheds or any otherplace where conventional recirculating, holding, septic or sewagesystems are too costly, impractical or impossible to use. Further, itfinds use in climates where water toilets will freeze. Morespecifically, the device can be installed in vacation homes, travelingconstruction office trailers, industrial buildings, tug boats, houseboats, warehouses, farms, mines, garages, marinas, fuel pumping andcommunicating relay stations, highway rest and toll stations and anyother place where convenience and economy are desired.

In the form of the device especially adapted for use by the railwayindustry, the device can be installed in cabooses, bunk or business carsand it can be installed as easily as a household dryer or an oil firedspace heater. A gas or fuel oil line, electrical connection and a flueare all that are required. The improved igniter gives sure-fire ignitionin all installations.

I claim:

1. An incinerating system comprising a combustion chamber, combustiblemeans for burning in the combustion chamber, means defining a spark gapin spark delivering proximity to said combustible means, oscillatormeans for applying a voltage across the spark gap for igniting thecombustible means, said oscillator comprising a core of magnetizablematerial capable of being driven into and out of saturation, windingmeans inductively coupled with said core, controllable conduction means,and circuit means connecting said controllable conduction means to saidwinding means for driving said core alternately into and out of magneticsaturation at a frequency controlled by the speed. of magnetization ofthe core and the magnetizing forces produced by said winding means.

2. The system of claim 1 wherein said winding means includes primarywinding means coupled by said circuit means to said controllableconducting means and secondary winding means magnetically coupled tosaid primary winding means, the out-put of said oscillator beingprovided across said secondary winding means.

3. The system of claim 1 wherein said controllable conduction meansincludes a pair of variable conduction devices, said circuit meansconnecting said pair of devices and said winding means as amultivibrator with a time constant controlled by the magnetizablematerial in said core.

4. The system of claim 3 wherein said winding means includes a firstprimary winding associated with one of said pair of devices and a secondprimary winding associated with the other of said pair of devices, andseries means connecting each of said primary windings in series with itsassociated variable conduction device.

5. The system of claim 4 wherein said winding means further includes athird primary winding mutually coupled to said first and second primarywindings, each of said variable conduction devices includes two outputelectrodes and at least one control electrode, said series meansconnecting the first and second primary windings in series with theoutput electrode of the associated devices, and control means couplingsaid third primary winding to the control electrodes of said pair ofdevices.

6. The system of claim 5 wherein said control electrodes of said one andother devices are coupled to opposite sides of said third primarywinding to alternately drive said devices into opposite conductionstates.

7. The system of claim 6 wherein said circuit means includes a source ofpotential, and resistive means connecting said potential source to oneof said control electrodes.

8. The system of claim 6 wherein said control means includes capacitormeans connected in series between one side of said third winding and thecontrol electrode of one of said devices.

9. The oscillator of claim 8 wherein said control means includes secondcapacitor means in the series connection for increasing the frequency ofoscillation.

10. An incinerating system comprising a combustion chamber, combustiblemeans for burning in the combustion chamber, means defining a spark gapin spark delivering proximity to said combustible means, and oscillatormeans for applying a voltage across the spark gap for igniting thecombustible means, and means for cooling said oscillator.

11. The system of claim 10 wherein said burning means is a fuel burnerhaving an air supply and said cooling means comprises a bleed line fromsaid air supply to blast air on said oscillator.

v UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Dated December25 1973 Patent No. 3,780,677

Inventor(s) Donald P. Frankel It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 5, line 20, delete "185" and insert -l84 Signed and sealed this9th day of April 197M.

LDEJA'EKIJ EJ-E.FLETUEER,JR. C. MARSHALL DAMN Attesting OfficerCommissioner of Patents FORM PO-105O (10-69)

1. An incinerating system comprising a combustion chamber, combustiblemeans for burning in the combustion chamber, means defining a spark gapin spark delivering proximity to said combustible means, oscillatormeans for applying a voltage across the spark gap for igniting thecombustible means, said oscillator comprising a core of magnetizablematerial capable of being driven into and out of saturation, windingmeans inductively coupled with said core, controllable conduction means,and circuit means connecting said controllable conduction means to saidwinding means for driving said core alternately into and out of magneticsaturation at a frequency controlled by the speed of magnetization ofthe core and the magnetizing forces produced by said winding means. 2.The system of claim 1 wherein said winding means includes primarywinding means coupled by said circuit means to said controllableconducting means and secondary winding means magnetically coupled tosaid primary winding means, the out-put of said oscillator beingprovided across said secondary winding means.
 3. The system of claim 1wherein said controllable conduction means includes a pair of variableconduction devices, said circuit means connecting said pair of devicesand said winding means as a multivibrator with a time constantcontrolled by the magnetizable material in said core.
 4. The system ofclaim 3 wherein said winding means includes a first primary windingassociated with one of said pair of devices and a second primary windingassociated with the other of said pair of devices, and series meansconnecting each of said primary windings in series with its associatedvariable conduction device.
 5. The system of claim 4 wherein saidwinding means further includes a third primary winding mutually coupledto said first and second primary windings, each of said variableconduction devices includes two output electrodes and at least onecontrol electrode, said series means connecting the first and secondprimary windings in series with the output electrode of the associateddevices, and control means coupling said third primary winding to thecontrol electrodes of said pair of devices.
 6. The system of claim 5wherein said control electrodes of said one and other devices arecoupled to opposite sides of said third primary winding to alternatelydrive said devices into opposite conduction states.
 7. The system ofclaim 6 wherein said circuit means includes a source of potential, andresistive means connecting said potential source to one of said controlelectrodes.
 8. The system of claim 6 wherein said control means includescapacitor means connected in series between one side of said thirdwinding and the control electrode of one of said devices.
 9. Theoscillator of claim 8 wherein said control means includes secondcapacitor means in the series connection for increasing the frequency ofoscillation.
 10. An incinerating system comprising a combustion chamber,combustible means for burning in the combustion chamber, means defininga spark gap in spark delivering proximity to said combustible means, andoscillator means for applying a voltage across the spark gap forigniting the combustible means, and means for cooling said oscillator.11. The system of claim 10 wherein said burning means is a fuel burnerhaving an air supply and said cooling means comprises a bleed line fromsaid air supply to blast air on said oscillator.